Frequently Asked Questions on Avian Influenza

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Coleen Jefferson
5 years ago
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1 Frequently Asked Questions on Avian Influenza What is bird flu (avian influenza) and how does it differ from seasonal flu and pandemic influenza? Avian influenza or bird flu is a disease of birds caused by type A strains of the influenza virus. It can affect all species of birds, some other animals (e.g. cats, horses) and can very rarely infect humans. Only the virus types of the H5 and H7 types are known to cause the highly pathogenic (HPAI) form of the disease. The most well-known example is the avian influenza subtype H5N1 viruses currently circulating in poultry in parts of Asia and northeast Africa, which have caused human disease and deaths since Other avian influenza subtypes, including H7N7 and H9N2, have also infected people. Some of these infections have been very severe and some have resulted in deaths, but many infections have been mild or even without symptoms in humans. Seasonal/ordinary influenza (flu) is an illness resulting from infection by a different type of influenza virus. It is highly infectious, spreading easily from person to person. It occurs each year during the winter period. What is pandemic influenza? Pandemic influenza is a type of influenza that occurs every few decades and which spreads quickly to affect most countries and regions around the world. Will the vaccine for seasonal influenza protect against avian flu? No, the seasonal influenza vaccine will not provide any protection against avian influenza. Does the virus spread easily from birds to humans? No. Since 2003 there have been less than 900 human cases of H5N1 globally. This is a small number compared with the huge number of birds affected and the large number of associated opportunities for human exposure, especially in areas where backyard flocks are common. Currently, it is not understood why some people, and not others, become infected after similar exposures. Does the virus spread between humans? To date, there have been only a few documented cases in which there is evidence to suggest person-to-person transmission however, at present, there is no evidence that that highly pathogenic strains of virus i.e.h5n1 and H7N9 virus has adapted to spread easily in humans. Further information on these clusters is available on the WHO website. Why are the H5 and N7 strains of concern to human health? The avian influenza H5 and N7 strains are of concern for human health for a number of reasons. 1

2 1. The first is the small risk of direct infection when the virus passes from poultry to humans and causes severe disease. Of the few avian influenza viruses that have crossed from poultry and infected humans, H5 and H7 strains have caused the largest number of cases of severe disease and death in humans. 2. A second risk, of even greater concern, is that the virus if given enough opportunities may change into a form that is highly infectious for humans and spreads easily from person to person. Such a change could mark the start of a global outbreak (a pandemic). Is it safe to eat poultry and poultry products? Yes. It is safe to eat poultry and poultry products. Avian influenza is not transmitted through cooked food and to date there is no evidence that anyone has become infected following the consumption of properly cooked poultry or poultry products. Careful preparation and eating properly cooked poultry and eggs will ensure that poultry and poultry products do not pose a threat to human health. Poultry should be cooked, so that it reaches temperatures of at least 70 C in all parts of the item, ensuring that it is piping hot all the way through, with no pink meat left and until the juices run clear. Consumers, caterers and food manufacturers should use and consume eggs as normal, following good hygiene practices. Use soap and hot water to wash hands after handling raw eggs and to clean surfaces and utensils that have come into contact with raw eggs. The World Health Organization advises that in avian infected areas eggs should be cooked until both the yolks and whites are solid. Make sure that other foods are not contaminated by raw poultry. This is important not only for avian flu, but also for preventing a range of other diseases transmitted through raw or undercooked poultry. If you are travelling to an area affected by bird flu, avoid unnecessary contact with poultry and poultry products and do not touch or eat raw or undercooked poultry, egg or duck dishes. If an outbreak of Avian Flu occurs, poultry and eggs from infected farms will be destroyed. Safe Food and the Food Safety Authority of Ireland have more information available. 2

3 How are animals affected by avian influenza? Wild birds may carry influenza viruses without becoming ill. Migratory waterfowl (most notably wild ducks) are the natural source of avian influenza viruses and these birds can carry the virus with no obvious harm. In domestic poultry, infection with avian influenza causes two main forms of disease, distinguished by low and high severity of disease. The low pathogenic (LPAI) form commonly causes only mild symptoms (ruffled feathers, a drop in egg production) and may easily go undetected. The highly pathogenic (HPAI) form is far more severe. It spreads very quickly through poultry flocks, affecting multiple internal organs, and has a mortality rate that can approach 100% often within 48 hours. How do outbreaks of avian influenza spread in flocks? Within a country affected by highly pathogenic avian influenza (HPAI) outbreaks in flocks, the disease can spread easily from farm to farm. Large amounts of virus can occur in bird droppings, contaminating dust and soil. Airborne virus can spread the disease from bird to bird, causing infection when the virus is inhaled. Contaminated equipment, vehicles, feed, cages or clothing especially shoes can carry the virus from farm to farm. The virus can also be carried on the feet and bodies of animals, such as rats, which act as carriers for spreading the disease. Droppings from infected wild birds can introduce the virus into both commercial and backyard poultry flocks. How can avian influenza be controlled in birds? The most important control measure is regular monitoring. For poultry, rapid destruction (culling) of all infected or exposed poultry, with proper disposal of the carcasses. Quarantining and full disinfection of farms are essential. Restrictions on the movement of live poultry, both within and between countries that are affected is another important control measure. More information on recent measures taken by the Department of Agriculture, Fisheries Food and the Marine (DAFM) to prevent an outbreak of HPAI in Ireland and guidelines for poultry flock owners is available on the Department of Agriculture, Food and the Marine website. A guidance document is available on the HPSC website describing both animal and human health actions when an outbreak of avian influenza occurs; as well as the public health management of contacts and of those involved in avian influenza outbreak control activities. 3

4 What public health advice about avian influenza is being offered to poultry flock owners and those who work with poultry? Poultry flock owners and those who work with poultry are being advised: If you suspect disease in your poultry Ask your vet for advice immediately Keep contact with the poultry to a minimum until the vet has assessed the situation Don t let anyone come into contact with the potentially infected poultry, i.e. keep people away Do not move poultry or poultry products e.g. feathers, eggs etc. or manure/litter from the premises Avoid the risk of infection from their flocks Wash hands (and arms if necessary) before eating, drinking, smoking, using the telephone, taking medication, applying make-up, inserting contact lenses Cover all new and existing cuts and grazes with waterproof dressings and/or gloves before starting work with poultry. If cuts and grazes occur, wash immediately with soap and running water and apply a waterproof dressing Avoid hand-mouth or hand-eye contact e.g. don t put pens or pencils in mouths or wipe your eyes with your hand Follow the bio security advice in the leaflets from the Department of Agriculture, Food and the Marine (DAFM). Get regular flu vaccine Get vaccinated against human flu. This will stop you catching human flu, and stops you from having human and bird flu at the same time. Having bird flu and human flu together could lead to changes (mutations) in the bird flu virus making it more infectious for humans. This is offered free to poultry owners. Your GP can arrange this for you. It does not protect against bird flu. What public health advice about avian influenza is being offered to hunters? Hunting associations and wildlife authorities should be aware that avian influenza viruses might be present in waterfowl hunted during the migratory season. Hunters are potentially at risk of infection from influenza viruses and other avian pathogens. Hunting, handling and dressing of shot waterfowl also carries the risk of spreading avian influenza viruses to susceptible poultry. Advice on the precautions to be followed by hunters has been issued by the Department of Agriculture, Food and the Marine. 4

5 How great a public health risk is avian influenza to Europe following the detection of human cases of H5N1? The risk to human health in Europe still remains low despite reports of human cases of H5N1 in Turkey in 2006 and Canada in The European Centre for Disease Prevention and Control (ECDC) in a risk assessment of the public health risk due to of influenza A/H5N1 in Europe states that the direct risk to the health of people in Europe from H5N1 virus is very low, but not zero. The risk is mostly in to certain groups of people (those who have close contact with infected domestic poultry). At present, for those people who have no contact with domestic or wild birds, the risk must be considered almost nonexistent. Further information on H5N1 and other strains may be obtained from the ECDC website. Countries in Europe including Ireland have reported avian influenza A (H5N8) viruses in wild birds, zoo birds and poultry holdings. No human infections with this virus have ever been reported world-wide. ECDC s updated rapid risk assessment concludes that the risk of transmission to the general public in Europe is considered to be very low. 5

FREQUENTLY ASKED QUESTIONS 1 Avian Influenza in Birds

FREQUENTLY ASKED QUESTIONS 1 Avian Influenza in Birds What is Avian Influenza? The disease commonly referred to as bird flu is an animal infection caused by the H5N1 virus. The virus occurs naturally among